The Telangana Rashtra Samiti on Tuesday night announced that it has decided to vote against the United Progressive Alliance government in the next week's confidence vote since the Congress had betrayed its demand for a separate Telangana state.

TRS chief K Chandrasekhar Rao, who had earlier served in the Union Cabinet and resigned over the Telangana issue, spoke to Bahujan Samaj Party chief and Uttar Pradesh Chief Minister Mayawati in the evening to work out a joint strategy against the UPA government.

The three MPs belonging to TRS and "about three to four MPs who are with me" will also vote against the UPA government, Rao told NDTV.

Rao said he will have a meeting with Mayawati in New Delhi on July 20 ahead of the trust vote on July 22.

In a setback to the Congress's efforts to garner the support of as many as MPs as possible for the trust vote that is expected to be a close affair, Rao said there is no going back on the decision to vote against the government.

"Our demand (for Telangana) is non-negotiable," Rao said.

Though TRS has three MPs in Parliament, one of them A Narendra, was expelled from the party. But TRS sources said that he too may vote against the government.

Rao, during his telephonic discussion with Mayawati, sought her support for a separate Telengana. She told Rao that BSP is in favour of Telangana state.

Mayawati's meeting with TRS though comes as a surprise as according to reports, she is also supposed to meet Telugu Desam Party chief N Chandrababu Naidu [Images] on July 19.

However with the BSP, TDP and also TRS having declared their opposition to the nuclear deal, Mayawati's meeting with the TDP and the TRS could well be an indicator of a growing third alliance against the Congress-led United National Progressive Alliance, which may gain strength over the next few days.